DE8520763U1 - Device for zig-zag folding of an infinite material web and for separating stacks - Google Patents

Description

• ·· ■* illt I· a ■ · t i··· it &igr;«&igr;*

•••ti Ii it ■ i

&bull; · · · < I i * &igr; k*a·· · · t ti in

Stw.: Zig-zag-^folding-cutting paper web-I Womakö file 679 - Nüftingen, July 16, 1985

Device for zigzag folding of an infinite material web and for separating stacks

The invention relates to a device for folding an endless web of thin material, in particular a paper web, alternately in opposite directions to form sheets of the same length connected by means of the folds, which lie one above the other in a zigzag shape, and for separating stacks of a defined number of sheets from the endless sequence of these sheets lying one above the other in a zigzag shape, for which purpose a table which can be moved into the fold and which interacts with a cutting device is provided for opening the fold.

Such devices for zigzag folding of infinite material webs into a sequence of sheets of the same size connected by folds and for separating stacks of a defined number of sheets are already known.

DE-OS 2 264 633, for example, shows such a device in which the zigzag folding is carried out by means of pulling devices in the form of roller chain tracks arranged to the right and left of a fed endless paper web. These roller chain tracks work together in their approach area in such a way that they alternately grasp the paper web at intervals along its length and fold it with each engagement. These alternating folds lead to sheets lying one on top of the other in a zigzag shape and connected to one another by folds.

In order to be able to separate defined stacks of these zigzag-folded sheets, a blade table is provided that can be moved into an open fold, the blade of which interacts with a roller so that separation takes place at the fold edge.

it·· if ' t I i

&bull; ·· · I * ti·*·

&bull; · · t « IIJ ₁ I I t · · i II < · I

&bull;t··· it i Dtttl

i! Zig-zag Faizen paper web cutting-&iacgr; Wömäko file 679 - Nürtingen, July 16, 1985

There is a constant effort to carry out this cutting cut for stack separation as cleanly and quickly as possible in order to disrupt the continuous folding process as little as possible.

The invention is therefore based on the task of further improving the separation of stacks so that it meets the increasing machine performance.

According to the invention, this is achieved in that a driven conveyor screw corresponding to the folds is arranged on both sides to form the zigzag stack, that the stack being formed is supported by lowerable support means and that the opening of the fold for the cutting process takes place by means of blowing air while simultaneously temporarily stopping the conveyor screw located on the opening side for the retractable table and simultaneously lowering the support means for the stack, so that immediately after the stack has been cut off by means of the cutting device interacting with the retracted table, the stopped conveyor screw can be started up again in phase-accurately and a new stack can be formed on the table that is still retracted.

This makes it possible to keep the interruption of the folding process very short. While the cut stack is being transported away, a new stack can form on the table that is still retracted. The conveyor screw drive is only interrupted for a minimum period of time from the formation of the fold opening to the separating cut.

Furthermore, the invention provides that a blowing air nozzle is provided for supplying the blowing air for opening the fold.
A further feature of the invention is that the

% · 4 ·« I i I ff ff ff ff ff 4 <

> ff ff · ti · ff ff ·

&bull; ff· I t f ■·*>·«

Stw.: Zig-zag folding - cutting paper web - I Womako file 679 - Nürtingen, July 16, 1985

Support means for the stack consists of a support rake, which can be lowered to the discharge level for the separated stack.

The invention is also characterized in that the cutting device interacting with the retractable table consists of a Hesse that can be moved along the fold to be separated.

According to the invention, the knife is guided longitudinally on an axis.

I'm ill! I'm lilt

i · ill

III·· ti · Mill

with zig-zag faizen paper web cutting-I Womako file 679 - Nurfcingen, July 16, 1985

The invention will be explained in more detail below using an exemplary embodiment. The drawings show

Figure 1 is a schematic representation of the device according to the invention,

Figures 2 to

15

20

25

30

35

the operation of the stack separation device in different stages.

11 ti·

1 /

, Il Il I··· ·· ·<■>

rl itf c · ·&igr;&igr;&igr;

III Il Il · IiIII

5tw·: Zig-zag folding-cutting paper web-I WomakG file 679 - Nürtingen, July 16, 1985

A paper web 1 (Figure 1) is drawn off from a supply (not shown) by means of a feed roller 2 and passes through a folding device 3 operating according to a known principle. This consists in a known manner of two pulling devices 3a, 3b, each of which consists of an endless carrier element 8a or 8b running over rollers 4a, 6a, 7a or 4b, 6b, 7b. Toothed belts are to be used here as carrier elements 8a, 8b, which are provided with rows of holes for holding the paper that are supplied with suction air along the length of the sheet format. The only schematic representation of the carrier elements 8a, 8b does not allow this design or the suction air boxes required for this, over which they run, to be seen in the drawing.

The endless paper web 1 is alternately grasped by the support elements 8a, 8b and folded into a series of zigzag-shaped sheets 9, which are grasped on both sides by conveyor screws 11a, 11b and formed into a stack 12. The stack 12 is supported by a support rake 13a designed to be lowerable. Below the frame 14 supporting the conveyor screws 11a, 11b, there is a table 16 that can be moved horizontally in the direction of the stack 12 and a knife 18a that can be moved along the fold 17. The knife 18a is guided on an axis 19 so that it can be moved longitudinally (perpendicular to the plane of the drawing).

In order to separate a stack 12 with a certain number of sheets from the endless sequence of zigzag-folded sheets, it is necessary to open the specific fold located at the separation point. To do this, according to Figure 2, the conveyor screw 11a is stopped, the support rake 13a is lowered in the direction of arrow 21 and blown air from a blowing air nozzle 22 is blown into the opening point, so that the table 16 is moved into the opened fold 17 in the direction of the

&bull; I · I * III * * tI II· « I * I Il Il ItI · · I *···

■» · t < I « t

&bull;&bull;ti· «lc t

&bull;&bull;&Kgr;« |r t

· ■ ■ ■ Ct«. C

Stw.: Zig-zag folding - cutting paper web - I Womako file 679 - Nürtingen, July 16, 1985

arrow 24 (Figure 3). The fold 17 is now separated at its edge using the knife 18a, whereby the knife 18a is guided with its blade in a slot 16a of the table 16. The conveyor screw 11a is then set in motion again in the correct phase so that, as shown in Figure 4, a new stack 12a can form on the table 16 which is still retracted, while the separated stack 12, which is lowered to the discharge level 26 by means of the support rake 13a, is discharged sideways. After the separated stack 12 has been discharged from the machine, the table 16 is moved back in the direction of the arrow 27 and the support rake 13a is moved upwards in the direction of the arrow 28 so that the position shown in Figure 1 is reached again and a new separation process can take place.

Stopping and starting the conveyor screw 11a is done by a known fast-switching clutch-brake combination, e.g. a Danfoss clutch, which will not be described in detail here.

ii kt till Ii ■ III Il

I I I I III

Claims (5)

Stw.: Zig-zag folding - cutting paper web - I Womako file 679 - Niirtingen, 13 November 1986 Protection claims 1. Device for folding an endless web of thin material, in particular a paper web, alternately in opposite directions to sheets of the same length connected by means of the folds, which lie one above the other in a zigzag shape, and for separating stacks of a defined number of sheets from the endless sequence of these zigzag-shaped sheets, for which purpose a table which can be moved into the fold and which interacts with a cutting device is provided to open the fold, characterized in that a driven conveyor screw (11a, 11b) corresponding to the folds is arranged on both sides to form the zigzag stack (12, 12a), that the stack (12) being formed is supported by support means (13) and that the conveyor screw (11a) arranged on the side from which the table (16) can be moved between the sheets (9) can be stopped and the Supporting means (13) are designed to be lowerable. 2. Device according to claim 1, characterized in that on the side on which the table (16) movable between the leaves (9) is located, a blowing air nozzle (22) is arranged, which is directed between the leaves (9) to be opened. 3. Device according to claim 1, characterized in that the support means (13) for the stack (12) consists of a support rake (13a) which can be lowered to a removal level (26) for the separated stack (12). 4. Device according to claim 1, characterized in that the cutting device (18) cooperating with the retractable table (16) consists of a &bull; 11·». · · Stw.: Zig-zag folding - cutting paper web - I Womako file 679 - Nürtingen, November 13, 1986 5 folds (17) movable knife (18a). 5. Device according to claim 4, characterized in that the knife (18a) is guided so as to be longitudinally displaceable on an axis (19). 10 25 30 35 «» «* &iacgr; * ·■ · * it·· t · t&igr;ti 1*1 · » # * * t I